1. Field of the Invention
The present invention relates to an analog-to-digital converting module for a light sensing device and related sensing device, and more particularly, to an analog-to-digital converting device with different operation modes and related sensing device.
2. Description of the Prior Art
The light sensing technology is widely used in many applications. For example, the ambient light sensor (ALS) is applied to the laptop computer and the cell phone to sense the intensity of the ambient light and automatically adjusts the backlight of the liquid crystal display (LCD) screen. The usage convenience is improved and the battery life is prolonged, therefore. The light sensor also can be utilized to measure the distance or location of an object. For example, the mobile device generally comprises the proximity sensor. Conventionally, the proximity sensor can be realized by various methods. For example, the types of the proximity sensor comprise the inductive sensor, the capacitive sensor, the magnetic sensor and the photoelectric sensor. Note that, the photoelectric sensor has gained popularity in recent years. In addition, other important applications of the light sensing technology, such as object presence detection and gesture recognition, also draw lots of attentions.
Generally, the light sensor needs an analog-to-digital converter to convert the analog voltage generated by sensing light to a digital signal processed by the digital circuits. In addition, the light sensor needs another analog-to-digital converter to calibrate the environment noise and to eliminate the effects of the environment noises. Because the specifications of the analog-to-digital converter for converting the analog voltage are different from those of the analog-to-digital converter for calibration environment noises, the light sensor use different analog-to-digital converters to convert the analog voltage and the environment noise. That is, at least two analog-to-digital converters are needed for realizing the light sensor. The manufacture cost of the light sensor increases, therefore. As can be seen from the above, the prior art needs to be improved.